The formula is simple: Divide the number of Advanced Placement, International Baccalaureate or other college-level tests a school gave in 2010 by the number of graduating seniors. While not a measure of the overall quality of the school, the rating can reveal the level of a high school's commitment to preparing average students for college.

The TAG Magnet at Townview was tops in 2010; it's fallen all the way to No. 2 . Other DISD schools making the best-of list: the Judge Barefoot Sanders Magnet Center For Public Service at Townview ( No. 64 ), the School of Business and Management at Townview ( No. 67 ), the School of Health Professions at Townview ( No. 68 ), the Booker T. Washington School for the Performing and Visual Arts ( No. 141 ), W.T. White ( No. 271 ), Woodrow ( No. 588 ) and Hillcrest ( No. 598 ). And the Cosmos Foundation-operated Harmony Science Academy also makes the list -- at No. 159 .